My invention pertains to apparatus for measuring selected parameters on railroad car wheels. More specifically, the invention pertains to apparatus for measuring the diameter of railroad car wheels and determining the radial tread thickness and flange height in order to provide a rotational inertia factor.
Present railroad classification yard speed control systems measure or determine various parameters of railroad cars being humped and whose speed is to be controlled. The systems also measure or otherwise predetermine various yard and track parameters. These elements of information are fed into the process control computer which determines the speed at which a car or cut of cars should leave the final retarder to couple with preceding cars in a designated track at a safe coupling speed. At present, the car parameters determined include the weight class of the car, its rolling resistance on both curved and tangent track, the length of the car or cut, and the number and spacing of wheel-axle units. The yard and track parameters include the slope and curvature of the various tracks, the distance-to-go to coupling, and wind or weather conditions. One car parameter presently not measured but factored into the computations from stored standard values is the rotational inertia of the car wheels. This parameter is proportional to wheel diameter and the wheel tread or rim radial thickness. In general, the larger the wheel diameter, the greater the rotational inertia. This factor tends to effect the downhill rolling resistance, slowing the initial acceleration as a car leaves the hump but prolonging its movement in the flatter storage tracks. The effect is more pronounced on light weight or empty cars. There is also a difference in the retarder effectiveness in slowing down the cars proportional to wheel diameters, smaller wheels providing more effective retardation. Thus, a next step toward improving the operation of the automatic classification yard is to automatically provide to the computer control apparatus a measurement of the diameter and the radial tread thickness of the wheels of each car. This information may be used to determine or establish the rotational inertia of the wheels on that car, which factor is then entered into the retarder speed control computations. Such apparatus could also indicate the safety condition of the wheel, i.e., the radial thickness or depth of the tread and the height of the flange, both of which must be within certain predetermined limits. Apparatus is available in the art to individually measure these parameters and indicate whether the safety conditions are satisfied but a combined apparatus will have a distinct advantage particularly when it provides the wheel diameter measurements for rotational inertia determination.
Accordingly, an object of my invention is apparatus to automatically measure selected parameters of the wheels of moving railroad cars.
Another object of the invention is an arrangement for measuring the diameter of a railroad car wheel while it is rolling along a track rail.
Another object of my invention is apparatus to measure the diameter of a railroad car wheel moving along a track rail and also determine if the wheel flange is in a safe condition.
A still further object of the invention is an arrangement for determining, through measurement of selected parameters, the rotational inertia of a railroad car wheel while it moves along a stretch of track rail.
A further object of the invention is a railroad car wheel measuring means using a plurality of sensors mounted along the rail to detect the passage of selected points on a wheel and logic means to register the diameter of the wheel in accordance with the time and order of detection.
It is also an object of my invention to provide means for measuring selected parameters of a railroad car wheel as it moves along a track rail to register indications of wheel diameter, radial tread thickness and flange height to determine whether tread and flange parameters are within safety limits.
Still another object of the invention is an arrangement of apparatus for providing indications of the rotational inertia of a railroad car wheel and the safety condition of the wheel by measurements of selected parameters while the wheel is moving along a track rail.
Other objects, features, and advantages of my invention will become apparent from the following description and accompanying drawings when taken with the appended claims.